A totally implantable and automatic defibrillator device has been proposed previously by M. Mirowski et al, and is disclosed in reissue patents, U.S. Pat. Nos. Re. 27,652 and 27,757. The implanted automatic implantable defibrillator (AID) device responds to the detection of cardiac malfunction; e.g. ventricular fibrillation, and automatically applies one or more high-energy defibrillation impluses to the heart. Thus, the patient's heart function is monitored by means which discriminate between normal and abnormal heart functioning and when an abnormal condition is detected, i.e. when fibrillation is occurring, a storage capacitor within the defibrillator unit is charged to a high voltage level, and is subsequently discharged as a defibrillation impluse applied to the patient's heart, unless the heart resumes normal functioning within a preselected time interval. If the initial defibrillation impluse fails to return the patient's heart to normal functioning, provision is made for automatically applying several additional defibrillation impluses.